GREENBELT, Md. (WUSA) -- Prince George's County Fire officials say for the second time in a week a vehicle has struck a Greenbelt fire engine. Last Saturday, two firefighters were injured after a vehicle failed to give the right-of-way to a fire engine on the Beltway. A week later, another vehicle ran into a fire engine, which was then struck by another vehicle. Two drivers are charged.

According to fire officials, at approximately 2:45 a.m. Saturday, Fire/EMS units responded to a crash on the Inner Loop between the Baltimore-Washington Parkway and the Annapolis Road interchanges. Engine 835 was giving "barrier protection" to the other units and personnel operating at the scene when a 2005 Lexus slammed into the rear and side of the Greenbelt engine. Fire officials say no one was on board the engine at the time of the collision and no firefighters were hurt.

More than $30,000 worth of damage was done to the engine, which had to be taken out of service. The other vehicle sustained major damage (see photos). The driver was taken into custody and was to be tested for impairment. The driver was then charged with numerous traffic violations.

Shortly after that collision, another vehicle struck the vehicle that hit the fire engine. This car just missed firefighters next to the damaged Greenbelt engine. The driver of this car fled, only to be stopped by police a short distance down the road. This driver was tested for impairment and charged with several traffic violations, say fire officials.

Fire officials say, however, if the engine had not been in place there could have been serious or fatal injuries to crews and others at the scene. During barrier protection, a fire engine acts as a shield to oncoming traffic and emergency lights and other items are used to alert drivers.

Spokesperson Mark Brady wrote in his blog post on Sunday: "I often hear from motorists when they question why the Fire/EMS Department blocks an extra lane or more of traffic on crash scenes. I tell them we are saving lives. Once again, 'barrier protection' has been the difference between going to a funeral and going to the repair shop."

Fire officials say that because the Greenbelt Volunteer Fire Department only two fire engines were damaged and will be out of service for a while, the department will have to use a reserve or borrow a fire engine until their fire engines can be repaired.